Spark-plug.



E. Q. WILLIAMS.

SPARK PLUG,

APPLICATION FILED APR. 16. I914.

Patented Nov. 27, 1917 FE I HJN z/mv TOR.

EDWARD Q. WILLIAMS, OF SYRACUSE, NEW YORK.

SPARK-PLUG.

Specification of Letters Patent.

Patented Nov. 27, 1917.

Application filed April 16, 1914. Serial No. 832,306.

To all whom it may concern:

Be it known that I, EDWARD Q. WILLIAMS, of Syracuse, N. Y., have invented certain new and useful Improvements in Spark- Plugs, of which the following is a description.

My invention comprises mainly the form and method of construction and assembling, and of particulars set forth.

The object of my invention is to produce a spark plug which shall be simply and cheaply manufactured, yet an eflicient, serviceable and reliable spark plug, practically equal to such as are now produced in more expensive manner.

The principal feature of my invention is the manner by which the parts are held within the body, by a cylindrical bushing, or equivalent, which in turn is held by a heading, or flange, or may be held in any manner.

-In carrying out my object, I bore the body or shell with the enlarged. cavity at the lower end thereof, which permits all tooling operations upon said body to be performed .from one end, and at a single setting in ordinary forming lathes; and I dispense with screw threads and other operations, except thread B, for attachingto the engine in the usual manner.

In the accompanying drawings, Figure 1. is a longitudinal section of a completed plug, of the simplest form.

2. 1s a cross section on the line as m,

Fig. 3, is a longitudinal section of the steel body or shell as first formed, before assembling the other parts, and illustrating the manner of producingthe shell from solid hexagonal steel bars.

Fig. 4. is a bushing thereof.

Figs. 5. 6. 7. 8. 9. 10. are modifications, in somewhat different forms, as may be preferred for any reason.

Figs. 11. 12. are end views of Figs. 5. and 6. respectively.

The construction of my improved spark plug comprises a steel body or shell A. with screw threads B, upon the exterior of its lower end, to screw into the engine in the usual manner. 7

This shell A, is bored hollow throughout, to admit and'contain the insulating stemP. preferably of porcelain, or mica, or other suitable material.

The stem P. is preferably formed with a collar or shoulder S. at about midway, more or less, of its length.

The body or shell .A. is bored for the greater part of its length with a sufliciently large cavity C, to admit and contain the collar S. of the insulating stem P. and for the remainder upper portion D. only sufliciently to contain the upper part P. of said stem, thus leaving a solid shoulder or inturned flange R. of the shell 'A. while the lower portion of said stem projects clownward within the cavity C. of the shell A.

Throughout the center of the length of the stem P, there extends the usual electrode E. to carry the sparking current, and of which the portion 70, extending below the stem constitutes one of the spark or firing points, and is usually of special material, while the upper or top end thereof is completed by a screw thread H. and nut N. thereon suitable for attaching the electric conduction wires from the coil, or it may be of any preferred type. WVithin the cavity C. and above the stem collar S. there may be placed a suitable packing 'K. to form a soft cushion between the shell and stem, and to form a gas tight joint at said point. p

A cylindrical bushing or ring G. is placed within the cavity C, the upper end of said bushing resting against the collar S. of the stem, holding the same firmly in position and pressing against the'shoulder or flange R. while the lower end of said bushing is held up by the lower edge of the shell being formed over F, by flanging, beading, spinning, compressing or otherwise, to hold the said bushing with an upward pressure, which compresses and holds all parts tight and sufficiently firmly in their respective positions, as will be readily understood from the drawings, yet sufiiciently permitting the necessary slight movement of parts by expansion and.

contraction, without destructive efi'ect.

. Another electrode It. may be set in the end certain small aperture t, surrounding the firing point p, which aperture 1?. may be round, or of other form, as shown in Figs. 6. 7., et cetera, and which comprises the other firing point t.

Another equivalent modification Fig. 5. instead of the last mentioned cap, is a flat circular end piece T. with aperture t.

The bushing G. may extend to the end of the shell as Fig. 1. or it may be of any length less as in Figs. 8. and 10. even to the form of a ring Fig. 7. or a washer Fig. 9. or by cutting into the side of the shell and turning the chip as a bead over the edge of the bushving as Fig. 9.

I am aware that spark plugs have been made with a bore tapering throughout, but such can only-be used with a stem of elastic material, as mica, being unsuitable for porcelain; While my form is suitable for either porcelain or mica, or other material.

The firing points 10. 25. may be any of the forms shown, or others.

I claim l. A spark plug comprising a shell threaded exterlorly at its inner end for engagement in an engine cylinder and provided at its outer end with an inturned flange, an in sulator element which extends longitudinally through said shell and is provided with a laterally extending collar, said insulating element comprising a portion extending below said collar, an electrode carried by said insulating element and a compressive rim)- disposed inside of said shell inwardly of sai' collar bearing outwardly thereagainst, said shell having an integral flange turned over therefrom and said ring being compressively bound between said flange and said collar.

2. A spark plug comprising a shell threaded exteriorly at its inner end for engagement in an engine cylinder and provided at its outer end with an integrally solid inturned flange, an insulator-element which extends longitudinally through said shell and is provided with a laterally extending collar, said insulating element comprising a portion extending below saidcollar, an electrode carried by said insulating element and a compression ring disposed inside of said shell inwardly of said collar bearing outwardly thereagainst, said shell having an integral flange mechanically turned Over at the inner end therefrom to compress said ring against said collar and said collar against said outer solid integral flange.

3. A spark plug comprising a shell threaded exteriorly at its inner end for engagement in an engine cylinder and provided at its outer end with an inturned flange, an insulating element which extends longitudinally through said shell and is provided with a laterally extending collar, said insulating element comprising a portion extending below said collar, an electrode carried by said insulating element, a compression ring disposed inside of said shell inwardly of said collar, said compression ring comprising a cylindrical portion having an over turned upper edge, the latter bearing against said laterally extending collar'of the insulating element, and an integral inturned flange carried by the inner end of said shell which engages the inner portion of said ring, said ring being compressively bound between said flange and said collar.

EDWARD Q. WILLIAMS.

Witnesses:

PAULINE A. HALL, ERNEST M. KnLLoco. 

